Travel sound source



- %Y 1936- A. MOL. NICOLSON 2,042,237

TRAVEL SOUND SOURCE Filed Oct. 17, 1931 3 Sheets-Sheet 1 AMI AMP.

AMP

v s ($3 INVENTOR Alexander M LEan Nicn lsnn QM/7w? ATTORNEY May 26, 1936- A. MCL. NICOLSON TRAVEL SOUND S OURCE 3 Sheets-Sheet 2 Filed Oct. 1'7, 1931 TO SPEAKERS TO 7 SOURCE I :1. E E

lllllllllllllli O llllll-llllllll TO SOURCE INVENTQR A1 BXanflEr' M L EH11 Nil: uls un ATTORNEY May 26,1936- A. MOL. NlCOLSON TRAVEL SOUND S OURCE Filed Oct. 17, 1951 3 Sheets-Sheet 3 En -i AMI ' INVVENTOR Alexander M L EH11 Nil: U15 [111 Y BY ATTORNEY Patented May 26, 1936 UNITED STATES PATENT OFFICE TRAVEL SOUND SOURCE Application October 17, 1931, Serial No. 569,427

14 Claims.

This invention relates to the transmission and reproduction of sound and particularly to the direct and indirect reproduction of sound with pictures and over public address systems.

An object of this invention is to reproduce sound having the phase and directional efiects of the original creative sources.

Another object of the invention is to reproduce a traveling sound source with the same characteristics as the original.

A further object of the invention is to produce kaleidoscopic acoustic efiects.

In the present development of the art of sound reproduction for large audiences with public address systems and sound motion picture installations there is a lack of complete coordination between the original sound source and its acoustic presentation and between the reproduced objects and the sounds therefrom, respectively. Certain corrective systems have been employed for producing a more natural reproduction such as binaural circuits and the like, but these systems fail to present the proper effect of a moving sound source. The present invention contemplates reproducing sound for an audience in which the sound actually travels in the same manner as the original sound source. For instance, the reproduction of a large orchestra is made natural inasmuch as the sounds of the instruments are reproduced at the positions they would have when the orchestra is actually present. Furthermore, in talking picture projections and especially where the large grandeur film is used, the moving of a source of sound across the screen will be reproduced from the exact point the source appears on the screen. In the case where sound sources are at different sides of the screen, the source of sound actually shifts with the reproduction and action of the sources.

As the recording of various individual sources can be made upon a single record it becomes necessary to segregate the time epochs of the various instruments and selectively direct their particular sound to the loud speakers or reproducers positioned at the places where the instruments were when the recording was made. A feature of this invention is the method of and means for separating or segregating the various frequencies or portions of a recording, to obtain selective and traveling sound effects. This is accomplished, in brief, by employing a plurality of speakers disposed within the presentation area, each of which is energized individually or in groups from a commutating arrangement, selected for the presentation to be rendered.

The apparatus is particularly adaptable to the production of acoustic kaleidoscopic effects in the same manner as light kaleidoscopic effects, that is, many combinations of sound projections will be progressively repeated without the repetition of the same combination over any normal period of operation.

The invention will be more fully understood by reference to the following description taken in conjunction with the accompanying drawings, in

which: 7

Fig. 1 is a schematic diagram of a'directional sound reproduction system;

Fig. 2 is a modification of the commutator of Fig. 1 especially adapted to kaleidoscopic reproduction.

Fig. 3 is a non-mechanical commutating arrangement, and; 7

Figs. 4 and 5 are plan and elevational views, respectively, of an interchangeable commutator system.

Referring to Fig. 1 specifically, a commutating device 5 has mounted thereon a plurality of contacting segments, 6 and I, having connected therebetween resistances 8 of various values for reasons to be explained hereinafter. A motor, not shown, rotates a brush I over the contacts 6 in serial order connecting a sourceof sound to a plurality of loud speakers I I. Although only a few contacts are shown a great many will be actually employed some of which will be connected to the same speakers. The speed of rotation of the arm I0 may usually be once for any selection but the contacts can be arranged for higher speed. Loud speakers II are shown positioned in an orchestra pit I2 above which may be a moving picture screen or a stage, but it is to be understood that the speakers may be disposed in any arrangement desired.

To the input side of the commutator are connected three types of sound sources. A sound source I4 includes a soundfilm I 5 with its associate light source I6 and photoelectric cell ll of any well known types. The output of this sound source is connected to an amplifier I8 where the electrical pickup currents are amplified before impression upon the commutator 5. Another sound source 20 is one comprising a phonograph record ZI with pickup device 22, sound therefrom being amplified in an amplifier 23 before impression on commutator 5. The third channel 25 includes a microphone 26 and amplifier 21, each channel being connected to the commutator by means of switches 28, 29, and 30 respectively. No amplifiers have been shown between the commutator 5 and loud speakers I I but such may be employed if 'more volume is required.

The three sound sources I4, 20, and 25, have been shown to illustrate that the system is adaptable to almost any type of sound source. For instance, an orchestra recording on the film [5 or disc 2! may be reproduced in loud speakers positioned in the orchestra pit l2, the brush I0 connecting the proper speakers into the output of the amplifier in a predetermined order. In op eration, therefore, any instrument which prodominated at the time of recording wil-l' doininate during reproduction, but the speaker at the position of the particular dominating instrument during a presentation will be the. reproducing medium. Furthermore, in the case of drums, which are generally located. at one side of the orchestra, the speakers located at the drums position will not only be the ones to reproduce the sound but will be particularly adapted to reproduce the frequencies .of the drums. Of course, the speakers; which more naturally reproduce the other instruments will be selected for their reproduction in a similar manner. The commutator will have a speed and the. proper arrangement of connections to obtain the desired selection in accordance with the presentation being made.

This' type of: commutator is well adapted to produce a traveling source of sound by energizing the speakers in a serial. order. The brush I0 is shown sufficientlywide to enablemore than one loud speaker to operate at the same time, thus producing acoustic shading effects. Further- 7 more, more than one rotating brush may be employed so that irregular selectivity can be ob tained at the reproducers. In the case of the microphone 25,. if it is desired to reproduce the voice of a person walking across the stage: or the sound of an inanimate object such as the. horn of an automobile. whichis moving, the proper sound may be presented at themicrophone 25, and due. to the serial operation of the reproducers I I, the effect is'a source of sound actually being moved across the characterized area. The resistances. 8 in the commutator'circuit permit distance effects tobe obtained by the proper shading of .the amplitude of the reproduced sound. a

In Fig.2 a different type of commutator which may be substituted for commutator 5 in. Fig.1 is illustrated. This commutator has a metallic annular ring in which hasbeen inserted insulating sections-36. A stationary brush 3'! is located on the inside of. the circumference of the ring, this brush being connected to one terminal of the sourcev of sound.v On the outside circumference of the :ring is a plurality of brushes 38 which make contact with the metallic sections thereof but which are insulated therefrom by the sections 36. These brushes are connected to loud speakers 'or amplifiers in the:- manner shown in Fig. 1, resistances 39 of varying values being inserted in the leads to determine the amount of energy delivered at eachrspeaker. A return conductor 40 completes the circuit between the sources of sound and the reproducers.

In the construction shown in Fig. 2 any desired arrangement of insulating sections may be employed to conform with the particular type of selection being 'reproduced. In the present arrangement the-number .of speakers actuated will be varied irregularly as the ring rotates as shown by the arrow while the amplitude will be controlled by the resistances 39. With such a device, therefore, it is possible to reproduce an erratic presentation of a play or a selection of music to produce a Kaleidoscopic effect. Of course, a particular selection can be reproduced in natural form by the proper pre-arrangement of segments 36 and brushes 38, but this construction lends itself readily to the reproduction ofv sound wherein loud speakers are distributed throughout an entire auditorium and a kaleidoscopic presentation is desired.

Referring to Fig. 3 an all electrical commutator is described in which ring electrode rails 42 are polarized to form an arc therebetween from a source of potential 43 under control of rheostat 44. The electrode rails 42 are positioned in a uniform magnetic field produced by current from a source 45 in field coils 46 and 41 which are arranged to produce lines of force pe pendicular to the arc, the current being under control of rheostat 48. As the are or electrical discharge is propagated around the circular. electrodes the light therefrom actuates a pair of electric cells 50 and 5|. It is to be. understood, of course, that more cells may be employed in any predetermined disposition about the rails, two being shown solely for the purposes of explanation. A similar system employing a traveling electrical discharge is, disclosed in my c0- pending application Serial No. 568,012, filed October 10, 1931.

The output of cell 50v is fed into an amplifier 52 and the output of cell 5| into an amplifier 53 each of which feed respective loud speakers 54 and 55. A grid biasing battery 56 with its associate resistance 51 determines the operating pointof one tube, in. amplifier 52, while grid biasing battery 58 and its associate resistance 59 is shown similarly supplying the amplifier 53. These biasing and polarizing batteries are sufficiently large and proportioned, to bias one tube of each amplifier so that the amplifiers are only operative at the time the light from the arc actuates the cells, the light removing the bias during that interval. In operation, therefore, the incoming signalis distributed and impressed upon the amplifiers and correspondingrreproducers in accordance with the rate of. propagation of the are along its rails. As the speed of the arc is controlled by the rheostats 44 and 43, a very accurate and flexible control of the distribution of the sound sources to the speakers is obtained. Furthermore, a more rapid commutation may be effected with this all electric system than with the mechanical types. The amplitude in each output circuit may be varied in this system in the same manner as described for the above systems while the addition of any practical number of photocells may be made.

Figs. 4 and 5 of the drawings show plan and elevational detail views respectively, of an interchangeable commutator system. The sound from a sound source comprising a disc and pickup device 6| is amplified in amplifier 62 and fed into the coinmutating device 63. This device includes a disc 64 upon which are mounted metallic conductive segments 65 over which passes. or rotates a brush 58 connected to the output of the amplifier 62. Connected to the segments 65 over conductors 65 which include resistances iii, are terminals 10. These terminals are connected to conductors 12 which may be grouped into a cable [3 for distribution to the reproducing de vices as shown in Fig. 1. Brush 68 is rotated by a motor 15 which may be energized over con:

order but will be actuated at random or in accordance with the particular reproduction being made. The resistances 61 control the amplitudes of the currents impressed upon the speakers.

The chief advantage of this commutating device is its flexibility. Standardized discs, having certain interconnections of contacts to correspond with certain recordings, may be quickly interchanged, permitting one device to handle any reproduction. That is, a disc is made up to accompany a certain recording each recording having one or more discs according to its length.

Many modifications of this selective reproducing system will occur to those skilled in the art, such as time signals, traffic warnings, and for various types of entertainment purposes in theatres and public auditoriums, to produce echo efiects and the like. It is also adapted to visual systems and any such equivalent systems are understood to be within the scope of the appended claims.

What is claimed is:

1. In an electrical reproducing system, a source of sound currents, a plurality of reproducing devices for transforming said electrical currents into sound waves, and means for selectively connecting certain of said reproducing devices to said source of sound waves in a predetermined order, said means including a moving electrical discharge device.

2. In a sound reproducing system, a source of electrical currents representing sound variations, a plurality of loud speakers for transforming said electrical currents into sound waves, and an electrodynamic arc device for connecting at least one of said speakers with said source of sound at certain time intervals according to the characteristics of the original sound waves.

3. In a system for the transmission and amplification of a source of sound waves, a pick-up device for transforming sound waves into electrical variations, a plurality of reproducing devices disposed about a listening space, and means for connecting said reproducers with said pickup device in a predetermined order to produce any moving effects of the original sound source, said means including a photoelectric cell for each of said reproducers activated in serial order by a moving electrical discharge.

4. In a transmission system, a pickup device for transforming recorded sound waves into electrical currents, means for amplifying said currents, a plurality of loud speakers adapted to transform said currents into the original sound waves, and a commutator intermediate said pickup device and speakers for selecting the loud speaker especially adapted to reproduce the electrical currents being transformed at that instant, said commutator having interchangeable disks with fixed connections adaptable for particular selections.

5. In a commutating system for sound repro duction, a plurality of contacts, a plurality of loud speakers, means for connecting said contacts with said loud speakers, a second plurality of contacts, means for interconnecting said pluralities of contacts with conductors of diiferent impedances, and means connecting a source of sound to said second plurality of contacts at predetermined intervals.

6. In an electrical transmission system, a source of electrical currents, a plurality of speakers for transforming said currents into sound, electrodes positioned in a magnetic field for producing a moving electrical discharge, a plurality of photoelectric devices adapted to transform light from said discharge into electric current impulses, and means for connecting said photoelectric devices with the individual circuits of said speakers for controlling the transmission between said source of sound and said speakers at mutually exclusive intervals.

'7. In a commutating system, a source of electrical currents, an amplifier for said currents, a plurality of reproducers for transforming said electric currents into sound waves, a commutating device intermediate said reproducers and said amplifiers comprising arotatable ring having insulating segments and a plurality of brushes individual to said speakers adapted to make contact with said ring between said segments one of which makes contact with said ring continuously, said commutating device connecting said reproducers with said source of electrical currents in a predetermined order, and conductors individual to said reproducers connecting said reproducers. and devices, said conductors having different impedances to vary the volume level of said electrical currents therein.

8. In a commutating device for selectively connecting a plurality of loud speakers with a source of electrical currents, a casing for said commutator, a disc mounted on said casing, a motor, a plurality of contacts on said disc connected to said loud speakers, and a brush slidable over said contacts by said motor for connecting said source with said speakers in a predetermined order dependent upon the source of sound, said disc being interchangeable with similar discs having a different order of connections.

9. In a commutating system for an electrical transmission circuit, a. plurality of loud speakers, an input circuit having therein electrical currents characterized by sound waves, a disc having a plurality of terminals for connection to said loud speakers, a plurality of fixed sliding contacts connected to said terminals in predetermined order, and means for making contact between the input circuit and said sliding contacts at a uniform rate.

10. A mechanical commutator comprising a casing, a motor in said casing, a rotatable element driven by said motor at a uniform rate, and a disc having mounted thereon a plurality of metallic elements for contacting with said rotating element and a second plurality of contacts connected to said first plurality of contacts in a predetermined order, said disc being interchangeable with similar discs having a different order of connections.

11. In an electrical transmission system, a source of electrical currents characterized by various wave forms, a plurality of speakers for reproducing said electrical currents in accordance to wave form, a photoelectric cell individual to each of said reproducers, said cell permitting transmission to its respective reproducer when actuated, and means for actuating said cells with a moving light source in accordance with the wave forms of said source of electrical currents.

12. In an electrical commutating system, a source of electrical currents, a plurality of reproducers for transforming said currents into sound waves, a plurality of conductors for connecting said source and each. of said reproducers,

separate means located in each of said conductors for controlling the amount of energy delivered by said source to each of said reproducers, and a rotatable element for determining the rder of connection of said source to said reproducers through said, conductors and said lastmentioned means.

13. In an electrical transmission system, a source of electrical currents having different components, a plurality of reproducers for transforming said currents into sound waves in accordance with said components, a plurality of conductors for connecting said source of electrical currents with each of said reproducers, separate means in each of said conductors for determining the amount of energy to be delivered to each of said reproducers, and a contact making element for connecting said source to said reproducers in theorderdetermined by the, char-' acterof, said components from said source.

14. In an electrical transmission system, a source of electrical currents having various components differing in character from time to time, a plurality of reproducers having diiferent characteristics for transforming said currents into sound waves, a plurality of conductors connecting said source of electrical currents to at least one of said reproducers at any instant of time, separate means in each of said conductors for determining the amount of energy to be delivered to each of said reproducers, and a moving contacting element for connecting said conductors to said source; the order of connection being predetermined by the known character of the components in said electrical currents.

ALEXANDER MCLEAN NICOLSON. 

